Calponin is an actin filament-associated regulatory protein expressed in smooth muscle and multiple types of non-muscle cells. Three isoforms of calponin are identified in vertebrate species. The structure-function relationship of calponin has been extensively investigated in terms of the regulation of smooth muscle contractility, in which its function was established as an inhibitor of actin-activated myosin ATPase. Besides modulating smooth muscle myofilaments, calponin also regulates the function of actin cytoskeleton with effects on cellular activities, such as adhesion, migration, division and differentiation. More recent studies demonstrated that calponin’s gene expression and protein turnover are both regulated by mechanical tension in correlation with its function as a stabilizer of the actin cytoskeleton and a regulator of cell motility. This finding also provides a novel system to study the interaction between extracellular mechanical environment and cellular functions. Summarizing recent research progresses, this review focuses on the role of calponin and its isoforms in mediating responses of cytoskeleton and cell motility to mechanical tension with examples for their functions in different cell types.